Design and production of electrical circuitry requires testing various attributes of a signal carried by the circuitry. These signal attributes include parameters such as bit error rate, clock slew, jitter, etc as well as other known parameters associated with electrical circuitry. Testing for these signal attributes is important in both conventional signaling, as well as in differential signaling.
Differential signaling differs from conventional signaling in that a differential signal is the difference in signal values between two entities. Low Voltage Differential Signaling (LVDS) is just one implementation of differential signaling, and comprises a data interface standard used for high-speed transmission of binary data over cooper wires and/or printed circuit board traces. Low Voltage Differential Signaling includes the use of a two-wire system for low power, low noise, and low amplitude data transmission. Low Voltage Differential Signaling is typically applied in a point-to-point physical layer interface such as component-to-component connections via printed circuit board traces. Other examples of differential signaling include high voltage differential signaling (HVDS). Differential signaling shows great promise for accelerating data transmission. However, with Differential signaling even greater attention must be paid to close tolerances in the impedance of transmission lines of a differential signaling interface, such as printed circuit board traces forming a differential pair of transmission lines.
Accordingly, whether investigators are testing conventional signaling or differential signaling, design and production of physical layer interfaces and conductive elements in electrical circuitry layouts would improve with more accurate signal testing.